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