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