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