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