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