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