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