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