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