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