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