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