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