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