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