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