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