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