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