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