This is from memory, so apologies if vastly wrong. North is the direction out of the solar system plane in the same direction as Earth's North. East is prograd

This is from memory, so apologies if vastly wrong. North is the direction out of the solar system plane in the same direction as Earth's North. East is prograde; tangent to the radial line from the sun, and in the direction of travel about the sun. Quickly googling I discovered that Saturn is considered to 'Rule the West' in some astrology circles, but alas I think that may not help this discussion.