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