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