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