It should be possible to convert the ethanol weight fraction (demonstration) to the mole fraction of ethanol in liquid (jpeg) via the equilibrium curve. Then you could transform the horizontal scale.
(By the way, I don't know the chemistry. For instance it does not seem to me the two units of enthalpy, kcal/kg and BTU / lb mole, are commensurable. There might be a transformation of the vertical scale needed as well. But perhaps I don't know what I'm talking about. Sorry.)