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