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