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