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