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)(25,26,31,32,30,35,27,34)(28,37,38,40,39,33,36,29)(1,2)(3,6)(4,5)(7,8)(9,11,13,18)(10,14,16,23)(12,20,21,17)(15,24,19,22)(25,27,30,31)(26,32,35,34)(28,38,39,36)(29,33,40,37)(9,12,13,21)(10,15,16,19)(11,17,18,20)(14,22,23,24)(25,28,30,39)(26,33,35,37)(27,36,31,38)(29,34,40,32)(2,5)(6,8)(10,16)(14,23)(15,19)(22,24)(25,29,31,37,30,40,27,33)(26,28,32,38,35,39,34,36)(1,3,4,7)(2,6,5,8)(25,27,30,31)(26,34,35,32)(28,38,39,36)(29,37,40,33)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.