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