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