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