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