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