RUBMEI

\documentclass[10pt,a4paper]{minimal}
\usepackage{tikz,tkz-euclide}
\begin{document}
\begin{center}
\begin{tikzpicture}[scale=2]
\tkzDefPoint(0,0){O} \tkzDefPoint(0,1){O1}
\tkzDefPoint(2^0.5/2,2^0.5/2){S1}
\tkzDefPoint(0,-1.5){Y1} \tkzDefPoint(0,2){Y2} \tkzDefPoint(-1.5,0){X1} \tkzDefPoint(2,0){X2}
\tkzDefPoint(-1,2){P1} \tkzDefPoint(2,-1){P2}
\tkzDrawSegments[thick,red](P1,P2) \tkzDrawSegments[thick,blue,-stealth](O,S1)
\tkzDrawSegments[-stealth,thick](Y1,Y2 X1,X2)
\tkzDrawCircle[dashed](O,O1)
\tkzLabelPoint[above,right](S1){$S(\frac{1}{3},\frac{1}{3},\frac{1}{3})$}
\end{tikzpicture}
\end{center}
\end{document}