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