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