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