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