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