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