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