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