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