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