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