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