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