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