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