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