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