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