As Masaki Kouda mentioned, you can switch from (celestial) North up
to galactic north up via Display... Inversion.

I'm not sure if you wanted that, or instead wanted some chart
projection other than the default stereographic one. To get different
projections, look in Settings... Projection. There isn't really a
"galactic projection", but if you set galactic north up, then any
projection that _is_ done will be relative to galactic coordinates.

-- Bill