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