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