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