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