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