graph G { graph [splines=false] node [shape=circle, texmode=math, fixedsize=True, width="0.4", style="ball color = green", label=""]; edge [style="snake=zigzag, green"]; a_1-- a_2 -- a_3 -- a_1; node [style="ball color = red", label=""]; edge [style="snake=snake, blue", color=red]; b_1 -- b_2 -- a_2; }