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