What are some of the sculptural elements depicted on President Thomas Wilson tomb?

I assume you mean President Woodrow Wilson. The top of the
tomb is decorated by a  large cross done in relief (see first link for a good picture).
And Wilson's name and the years he lived are carved into the top as well. The sides of
the tomb are decorated with columns carved in low relief, which echo the huge columns
that form the room itself.

The floor of the room the tomb
is in is carved with the seal of the president of the United
States.