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