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