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