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