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