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