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