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