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