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