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