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