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)(14,19)(18,22)(20,23)(21,24)(25,26)(27,29)(28,33)(30,35)(31,36)(32,34)(37,39)(38,40) involution — undirected(1,2,5,6)(3,7,4,8)(25,27,31,34)(26,32,36,29)(28,38,39,35)(30,37,40,33)(1,3,5,4)(2,7,6,8)(9,11)(10,14)(12,18)(13,19)(15,21)(16,17)(20,24)(22,23)(25,28,31,39)(26,33,36,37)(27,35,34,38)(29,30,32,40)(9,12,13,20)(10,15,17,23)(11,18,19,24)(14,21,16,22)(25,29,31,32)(26,34,36,27)(28,30,39,40)(33,38,37,35)(1,3,5,4)(2,7,6,8)(9,11)(10,16)(12,18)(13,19)(14,17)(15,22)(20,24)(21,23)(25,30)(26,35)(27,37)(28,32)(29,39)(31,40)(33,34)(36,38)(1,4,5,3)(2,8,6,7)(9,10)(11,14)(12,15)(13,17)(16,19)(18,21)(20,23)(22,24)(25,26)(27,32)(28,33)(29,34)(30,38)(31,36)(35,40)(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.