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