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