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