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