Изменения

a [label="" pos="0,1!" style=filled fillcolor=black height=0.3 width=0.3]; b [label="" pos="-0.95,0.3!" style=filled fillcolor=gray height=0.3 width=0.3]; c [label="" pos="0.95,0.3!" style=filled fillcolor=gray height=0.3 width=0.3]; d [label="" pos="-0.59,-0.81!" style=filled fillcolor=gray height=0.3 width=0.3]; e [label="" pos="0.59,-0.81!" style=filled fillcolor=gray height=0.3 width=0.3]; a -> b [label="5" style=bold] a -> c [label="5" style=bold] c -> b [label="2" style=bold] d -> e [label="2" style=bold] d -> b [label="1" style=bold] b -> d [label="1" style=bold] e -> c [label="1" style=bold] c -> e [label="1" style=bold]