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