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