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