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