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)(12,24,27,37,25,31,40,38)(17,33,35,39,34,22,36,26)(1,2)(3,6)(4,5)(7,8)(9,11,14,13,15,23,29,30)(10,16,19,28,21,18,20,32)(12,22,27,26,25,33,40,39)(17,31,35,38,34,24,36,37)(2,5)(6,8)(9,12,23,33,14,27,30,39,15,25,11,22,29,40,13,26)(10,17,28,38,20,36,16,31,21,34,32,37,19,35,18,24)(1,3,4,7)(2,6,5,8)(12,25)(17,34)(22,33)(24,31)(26,39)(27,40)(35,36)(37,38)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.