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