import arcpy

# C:temptest.mxd is a blank map
mxd = arcpy.mapping.MapDocument(r"C:temptest.mxd")
df = arcpy.mapping.ListDataFrames(mxd)[0]
arcpy.MakeFeatureLayer_management(r"C:temptest.mdbAnnoFC","annoFL")
annoLayer = arcpy.mapping.Layer("annoFL")
arcpy.mapping.AddLayer(df,annoLayer)
mxd.save()