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