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)(25,26,29,33)(27,34,30,31)(28,36,37,39)(32,35,40,38)(1,3,4,8)(2,5,6,7)(10,14)(15,23)(16,21)(17,24)(25,27,29,30)(26,31,33,34)(28,35,37,38)(32,39,40,36)(9,11,12,18)(10,15,14,23)(13,22,20,19)(16,24,21,17)(25,28,29,37)(26,32,33,40)(27,35,30,38)(31,39,34,36)(26,31)(27,30)(32,39)(33,34)(35,38)(36,40) 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.