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