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