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