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