\psset{unit=0.75cm}
%
\pspicture(-3,-1.5)(3,1.5)
%\showgrid
% Red arcs:
\redlinestyle
\psline(-2,-1)(-2,1)
\psline(2,-1)(2,0)(3,0)
% Green arcs:
\greenlinestyle
\psline(-3,0)(-1,0)
\psline(1,0)(2,0)(2,1)
% Points
\psset{linewidth=0.07,linestyle=solid,linecolor=black,fillstyle=solid,fillcolor=white}
\pscircle(-2,0){0.18}
\pscircle(2,0){0.18}
% Recolouring paths
\psset{linewidth=0.1,linecolor=gray,linestyle=solid}
\psline[linearc=0.2](-2.2,-0.9)(-2.2,-0.2)(-2.9,-0.2)
\psline[linearc=0.2](-1.1,0.2)(-1.8,0.2)(-1.8,0.9)
\psline[linearc=0.2](1.8,-0.9)(1.8,-0.2)(1.1,-0.2)
\psline[linearc=0.2](2.9,0.2)(2.2,0.2)(2.2,0.9)
\endpspicture