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