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