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