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