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