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