\definecolor{myblue}{HTML}{0000FF}
\begin{tikzpicture}[>=latex, node distance=1cm, on grid, auto]%, scale=0.6, transform shape]

\node (S2) [rectangle, minimum size=0.5mm] {};
\path (S2.east)+(0.25,-1) node (B1) [draw, regular polygon, regular polygon
sides=5, minimum size=1cm, color=myblue] {}; %{B};

\path[-,color=myblue] (S2) edge (B1);

\path (S2.west)+(-1,-0.5) node (arrow) [minimum size=0.5cm] {$\longrightarrow$};
\path (arrow.west)+(-0.5,0) node (B) {B};

\end{tikzpicture}