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