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