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