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