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