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