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