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