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)(25,26,32,40,30,28,31,35)(27,36,29,34,37,33,38,39)(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)(26,33)(28,36)(29,32)(30,37)(31,38)(34,35)(39,40) involution — undirected(2,5)(6,7)(25,28,30,26)(27,36,37,33)(29,39,38,34)(31,35,32,40)(9,12,13,21)(10,15,16,20)(11,18,19,24)(14,22,17,23)(25,29,30,38)(26,34,28,39)(27,32,37,31)(33,35,36,40)(1,3,4,8)(2,6,5,7)(11,19)(14,17)(18,24)(22,23)(27,37)(29,38)(33,36)(34,39)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.