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