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