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