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