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