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