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