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