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