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