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