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