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