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