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