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