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