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