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