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