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