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