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