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