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