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