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