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