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