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