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