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