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