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