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