Apparently you could use meshio python package (GitHub - nschloe/meshio: input/output for many mesh formats) to convert CGAL structures to .vtk file format.
Perhaps, pylgamesh (GitHub - nschloe/pygalmesh: A Python frontend to CGAL's mesh generators.) has enough CGAL functionality for you. In that case, meshio interface is already integrated.
Be careful with licence, as Andras Lasso pointed.
Most of CGAL packages are GPL, and whole pylgamesh too:
pygalmesh/LICENSE at main · nschloe/pygalmesh · GitHub