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