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