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