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