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