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