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