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)(11,15)(12,21)(13,16)(14,17)(18,24)(19,22)(20,23)(27,33)(28,36)(31,34)(32,37)(1,3,5,8)(2,6,4,7)(9,11,14,20)(10,15,17,23)(12,18,16,22)(13,19,21,24)(25,26,30,29)(27,34,33,31)(28,32,36,37)(35,40,39,38)(9,12,14,16)(10,13,17,21)(11,18,20,22)(15,19,23,24)(25,27,30,33)(26,31,29,34)(28,35,36,39)(32,38,37,40)(1,2,5,4)(3,6,8,7)(9,11)(10,15)(12,18)(13,19)(14,20)(16,22)(17,23)(21,24)(25,28)(26,32)(27,35)(29,37)(30,36)(31,38)(33,39)(34,40)(1,2,5,4)(3,6,8,7)(9,10)(11,15)(12,13)(14,17)(16,21)(18,19)(20,23)(22,24)(25,26,30,29)(27,31,33,34)(28,32,36,37)(35,38,39,40)(1,4,5,2)(3,7,8,6)(9,13)(10,16)(11,19)(12,17)(14,21)(15,22)(18,23)(20,24)(25,29,30,26)(27,34,33,31)(28,37,36,32)(35,40,39,38)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.