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