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