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