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