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