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