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