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