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