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)(14,19)(16,22)(18,24)(21,23)(25,26,31,34)(27,37,33,40)(28,38,32,39)(29,36,30,35)(1,2)(3,5)(4,6)(7,8)(9,11,13,18)(10,14,15,23)(12,21,22,19)(16,24,20,17)(25,27,31,33)(26,32,34,28)(29,39,30,38)(35,40,36,37)(1,3)(2,5)(4,7)(6,8)(9,10)(11,14)(12,16)(13,15)(17,19)(18,23)(20,22)(21,24)(25,28,31,32)(26,33,34,27)(29,37,30,40)(35,38,36,39)(10,15)(11,18)(16,20)(19,21)(26,34)(28,32)(35,36)(37,40) 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.