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