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