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