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