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