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