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