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