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