One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,7,5,3,8,6)(9,10)(11,21)(12,26,30,34)(13,19)(14,18)(15,20)(16,23)(17,28,35,29)(22,37,39,31)(24,32)(25,36)(27,40,38,33)(9,11)(10,16)(12,27)(13,24)(14,23)(15,25)(17,33)(18,36)(19,21)(20,32)(22,29)(26,37)(28,39)(30,38)(31,34)(35,40) involution — undirected(1,3)(2,5)(4,6)(7,8)(9,12,13,28,15,30,14,29)(10,17,18,34,20,35,19,26)(11,22,23,38,25,39,24,27)(16,31,21,33,32,37,36,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.