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