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