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