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