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