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