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