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