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