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