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