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