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