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