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