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