\documentclass[12pt,a4paper]{article}

\usepackage{allhelv}
\usepackage{color}
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{gastex}
\usepackage[noend]{algorithm2e}

\begin{document}

\pagestyle{empty}

\begin{Huge}
\begin{picture}( 150, 150 )

\put(100,100){\line( 1, 0){100}}
\put(100,100){\line(-1, 0){100}}
\put(100,100){\line( 0, 1){100}}
\put(100,100){\line( 0,-1){100}}

\put(100,100){\vector( 1, 0){80}}
\put(100,100){\vector(-1, 0){80}}
\put(100,100){\vector( 0, 1){80}}
\put(100,100){\vector( 0,-1){80}}
\put(100,100){\vector( 1, 1){80}}
\put(100,100){\vector(-1, 1){80}}
\put(100,100){\vector( 1,-1){80}}
\put(100,100){\vector(-1,-1){80}}

\put(100,180){\circle*{1}}
\put(100, 20){\circle*{1}}
\put(180,100){\circle*{1}}
\put( 20,100){\circle*{1}}

\put( 90,180){$ i$}
\put(110,180){$\omega_8^2$}
\put( 90, 20){$-i$}
\put(110, 20){$\omega_8^6$}
\put( 20, 90){$-1$}
\put( 20,110){$\omega_8^4$}
\put(180, 90){$-1$}
\put(180,110){$\omega_8^0=\omega_8^8$}

\put(185,185){$\omega_8^1$}
\put( 18,185){$\omega_8^3$}
\put(185, 15){$\omega_8^7$}
\put( 18, 15){$\omega_8^5$}

\end{picture}
\end{Huge}

\end{document}