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