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