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