\documentclass[border=10]{standalone}
\usepackage{tikz}

\begin{document}

\begin{tikzpicture}
\fill[gray!50!white] (0,0) circle (1cm);
\draw (0,0) circle (1cm);
\def\luku{1.5}
\draw[->] (-\luku,0)--(\luku,0) node[below left]{$x$};
\draw[->] (0,-\luku)--(0,\luku) node[below left]{$y$};
\end{tikzpicture}

\end{document}