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