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