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