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