\documentclass[tikz]{standalone}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[ngerman]{babel}
%\usetikzlibrary{...}% tikz package already loaded by 'tikz' option

\definecolor{informatik}{HTML}{73A1EC}
\definecolor{wahlpflicht}{HTML}{EEEEEE}
\definecolor{wahl}{HTML}{DDDDDD}
\definecolor{methodik}{HTML}{FFFF77}
\definecolor{sonstige}{HTML}{FF9966}
\definecolor{neben1}{HTML}{77AA44}
\definecolor{neben2}{HTML}{FFBB44}
\definecolor{neben3}{HTML}{4477AA}
\definecolor{cis-natinf}{HTML}{FFBB44}
\definecolor{cis-nat}{HTML}{E23E38}
\definecolor{abschluss}{HTML}{0055AA}
\definecolor{grau}{HTML}{CCCCCC}


\tikzset{
    modul/.style={
        line width=1mm,
        font={\scriptsize\bf\sffamily},
        align=center
    },
    big/.style={
        font={\large\sffamily},
    },
    box/.style={
    },
    semester/.style={
        font={\bf\sffamily},
        anchor=east,
        yshift=0.5cm,
        xshift=-0.2cm
    }
}

\begin{document}
    \begin{tikzpicture}[scale=1.0]
        \draw[lightgray,thick] (0, 0) grid (10, 6);
        \node[semester] at (0, 5) {WS1};
        \path[box,fill=informatik]  (0.050000, 5.950000) rectangle (1.950000, 5.050000);
        \path[box,fill=informatik]  (2.050000, 5.950000) rectangle (4.950000, 5.050000);
        \path[box,fill=informatik]  (5.050000, 5.950000) rectangle (7.950000, 5.050000);
        \path[box,fill=informatik]  (8.050000, 5.950000) rectangle (9.950000, 5.050000);
        \node[semester] at (0, 4) {SS1};
        \path[box,fill=informatik]  (0.050000, 4.950000) rectangle (1.950000, 4.050000);
        \path[box,fill=informatik]  (2.050000, 4.950000) rectangle (4.950000, 4.050000);
        \path[box,fill=informatik]  (2.050000, 5.100000) rectangle (4.950000, 4.900000);
        \path[box,fill=methodik]  (5.050000, 4.950000) rectangle (5.950000, 4.050000);
        \path[box,fill=methodik]  (6.050000, 4.950000) rectangle (6.950000, 4.050000);
        \path[box,fill=informatik]  (7.050000, 4.950000) rectangle (9.950000, 4.050000);
        \node[semester] at (0, 3) {WS2};
        \path[box,fill=informatik]  (0.050000, 3.950000) rectangle (1.950000, 3.050000);
        \path[box,fill=wahlpflicht]  (2.050000, 3.950000) rectangle (9.950000, 3.050000);
        \node[semester] at (0, 2) {SS2};
        \path[box,fill=sonstige]  (0.050000, 2.950000) rectangle (1.950000, 2.050000);
        \path[box,fill=wahlpflicht]  (2.050000, 2.950000) rectangle (9.950000, 2.050000);
        \node[semester] at (0, 1) {WS3};
        \path[box,fill=wahlpflicht]  (0.050000, 1.950000) rectangle (2.950000, 1.050000);
        \path[box,fill=wahl]  (3.050000, 1.950000) rectangle (5.950000, 1.050000);
        \path[box,fill=sonstige]  (6.050000, 1.950000) rectangle (8.950000, 1.050000);
        \path[box,fill=methodik]  (9.050000, 1.950000) rectangle (9.950000, 1.050000);
        \node[semester] at (0, 0) {SS3};
        \path[box,fill=wahlpflicht]  (0.050000, 0.950000) rectangle (2.950000, 0.050000);
        \path[box,fill=wahl]  (3.050000, 0.950000) rectangle (5.950000, 0.050000);
        \path[box,fill=abschluss]  (6.050000, 0.950000) rectangle (9.950000, 0.050000);
        \node[modul] at (1.000000, 5.500000) {Software-\\entwicklung I};
        \node[modul] at (1.000000, 4.500000) {Software-\\entwicklung II};
        \node[modul] at (3.500000, 5.000000) {Mathematik für Studierende\\der Informatik};
        \node[modul] at (6.500000, 5.500000) {Rechnerstrukturen};
        \node[modul] at (9.000000, 5.500000) {Informatik im\\Kontext};
        \node[modul] at (5.500000, 4.500000) {Meth.\\komp.};
        \node[modul] at (6.500000, 4.500000) {Pro-\\seminar};
        \node[modul] at (8.500000, 4.500000) {Formale Grundlagen\\der Informatik I};
        \node[modul] at (1.000000, 3.500000) {Algorithmen \&\\Datenstrukturen};
        \node[modul] at (6.000000, 3.500000) {Wahlpflicht 24 LP};
        \node[modul] at (1.000000, 2.500000) {Praktikum};
        \node[modul] at (6.000000, 2.500000) {Wahlpflicht 24 LP};
        \node[modul] at (1.500000, 1.500000) {Wahlpflicht 9 LP};
        \node[modul] at (4.500000, 1.500000) {Wahl};
        \node[modul] at (7.500000, 1.500000) {Projekt};
        \node[modul] at (9.500000, 1.500000) {Seminar};
        \node[modul] at (1.500000, 0.500000) {Wahlpflicht 9 LP};
        \node[modul] at (4.500000, 0.500000) {Wahl};
        \node[modul] at (8.000000, 0.500000) {Abschlussmodul\\(Bachelorarbeit)};

    \end{tikzpicture}
\end{document}