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