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)(15,17)(16,20)(22,23)(25,26,30,31)(27,32,38,35)(28,29,34,33)(36,39,40,37)(2,3)(6,7)(9,10)(11,17)(12,16)(13,14)(15,18)(19,23)(20,21)(22,24)(25,26,30,31)(27,35,38,32)(28,29,34,33)(36,37,40,39)(1,3,5,2)(4,7,8,6)(11,18)(15,17)(19,24)(22,23)(26,31)(28,34)(32,35)(36,40)(1,4,5,8)(2,6,3,7)(9,10)(11,15)(12,20)(13,14)(16,21)(17,18)(19,23)(22,24)(25,27)(26,32)(28,36)(29,39)(30,38)(31,35)(33,37)(34,40)(9,11)(10,15)(12,19)(13,18)(14,17)(16,22)(20,23)(21,24)(25,28,30,34)(26,33,31,29)(27,36,38,40)(32,37,35,39)(9,12,13,21)(10,16,14,20)(11,19,18,24)(15,22,17,23)(25,29,30,33)(26,34,31,28)(27,37,38,39)(32,36,35,40)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.