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