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