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