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