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