In the Western occult tradition, each planet can be represented by a seal or diagram. The seal is based off of the planet's magic square, with the seal theoretically touching every number within the square, although in practice that is not always apparently the case.
The Seal of Saturn follows the convention of overlapping every number of the magic square of Saturn in a distinctly orderly fashion. The upward pointing triangle includes numbers 1, 2, and 3. The diagonal line touches 4, 5, and 6, and the bottom-pointing triangle includes 7, 8, and 9.
The circles appear to be for aesthetic reasons.