Here are two approaches:
1) Make nodes/fonts smaller
2) Make graph canvas larger
import pylab
import networkx as nx
G=nx.cycle_graph(80)
pos=nx.circular_layout(G)
pylab.figure(1)
nx.draw(G,pos)
pylab.figure(2)
nx.draw(G,pos,node_size=60,font_size=8) # smaller nodes and fonts
pylab.figure(3,figsize=(12,12)) # larger figure size
nx.draw(G,pos)
pylab.show()
Aric