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