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