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