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