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