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