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