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