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)(11,17)(12,15)(13,16)(14,19)(18,23)(20,22)(21,24)(25,26,31,29,30,34,40,39)(27,33,36,35,28,32,38,37)(9,11,13,19)(10,14,16,17)(12,20,21,18)(15,23,24,22)(25,27,30,28)(26,32,34,33)(29,37,39,35)(31,36,40,38)(1,3,5,4)(2,6,7,8)(25,28,30,27)(26,33,34,32)(29,35,39,37)(31,38,40,36)(1,4,5,3)(2,6,7,8)(9,12,13,21)(10,15,16,24)(11,18,19,20)(14,22,17,23)(27,28)(32,33)(35,37)(36,38)(10,16)(14,17)(15,24)(22,23)(25,29,31,34,30,39,40,26)(27,35,36,32,28,37,38,33)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.