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)(25,26,31,36)(27,37,39,32)(28,33,29,34)(30,35,40,38)(2,5)(6,7)(9,10,14,11)(12,17,20,15)(13,16,21,18)(19,23,24,22)(25,27)(26,32)(28,38)(29,35)(30,34)(31,39)(33,40)(36,37)(1,2)(3,6)(4,5)(7,8)(10,11)(15,17)(16,18)(22,23)(25,28,31,29)(26,33,36,34)(27,38,39,35)(30,32,40,37)(9,11,14,10)(12,17,20,15)(13,18,21,16)(19,23,24,22)(25,26)(27,32)(28,33)(29,34)(30,35)(31,36)(37,39)(38,40)(1,2)(3,7)(4,5)(6,8)(9,12,14,20)(10,15,11,17)(13,19,21,24)(16,22,18,23)(25,29,31,28)(26,34,36,33)(27,38,39,35)(30,32,40,37)(1,3)(2,6)(4,8)(5,7)(9,13,14,21)(10,16,11,18)(12,19,20,24)(15,22,17,23)(25,30,31,40)(26,35,36,38)(27,34,39,33)(28,32,29,37)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.