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