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