One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,8)(5,6)(9,10)(11,19)(12,24)(13,27)(14,18)(15,20)(16,26)(17,21)(22,36)(23,32)(25,39)(28,38)(29,34)(30,35)(31,33)(37,40) involution — undirected(2,6)(7,8)(11,20)(12,25)(13,21)(15,19)(17,27)(22,37)(23,34)(24,39)(28,31)(29,32)(33,38)(36,40) involution — undirected(1,3,5,4)(2,7,6,8)(9,11,21,34,14,23,13,20)(10,15,27,32,18,29,17,19)(12,22,35,37,25,38,26,33)(16,28,39,40,30,36,24,31)(1,4,5,3)(2,8,6,7)(9,12,13,26,14,25,21,35)(10,16,17,24,18,30,27,39)(11,22,20,33,23,38,34,37)(15,28,19,31,29,36,32,40)(2,6)(7,8)(11,23)(15,29)(19,32)(20,34)(22,38)(28,36)(31,40)(33,37) involution — undirectedA 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.