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