(Image is Zn + CuSO4
Cu + ZnSO4
, then Zn0
in case it breaks, and for search assistance)
You can think of the sulfate ion perhaps as a "super-atom" that doesn't get changed in this reaction, or if you prefer you can split SO42-
further up into S6+
. Note that sulfur doesn't always have a -2 oxidation state (and is very unlikely to exist by itself as a 6+ ion.