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