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