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