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