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