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