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