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