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