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