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