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