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