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