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