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