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