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