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