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