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