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