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