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