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