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