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