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