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)(11,22)(12,18)(13,19)(14,17)(15,33)(16,25)(20,30)(21,29)(23,37)(24,34)(26,40)(27,36)(28,35)(31,38)(32,39) involution — undirected(2,5)(6,8)(9,11)(10,16)(12,24)(13,25)(14,32)(15,23)(17,36)(18,35)(19,22)(20,37)(21,34)(26,30)(27,31)(28,29)(33,40)(38,39) involution — undirected(1,3)(2,6)(4,7)(5,8)(10,17)(11,23)(12,29)(14,30)(15,31)(16,34)(18,33)(19,38)(20,21)(22,35)(24,27)(25,26)(28,32)(37,40) involution — undirected(3,7)(6,8)(9,12,13,29)(10,18,19,21)(11,24,25,28)(14,30,31,15)(16,35,22,34)(17,20,38,33)(23,32,26,27)(36,37,39,40)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.