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