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