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