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