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