How to horizontally align child nodes with the graphdrawing library of TikZ 3.0?

Instead every node={align=left} in tikzpicture parameters you should say:

every node/.style={anchor=west}

Result:

Upgrade: To my taste, regarding to edited questions, the following solution looks nicer:

\documentclass[tikz,border=10pt]{standalone}
\usetikzlibrary{graphdrawing, graphs}
\usegdlibrary{trees}

\begin{document}
\begin{tikzpicture}[>=stealth,
every node/.style={anchor=west}]            % <---
\graph [tree layout, grow'=right, 
        fresh nodes, level distance=0.5in,
        sibling distance=0.1in
                    ]
    {
        4 -> {
          3 -> { 1 -> { 5, " " }, 2,2 },
          3 -> { 1, 2, 2 },
          3 -> [head anchor=west]{ 1, 2, 2222}  % head anchor=west can be 
                                                % mowed to graph preamble
        }
    };
\end{tikzpicture}
\end{document}

It gives:

Note: MWE should be compiled by LuaLaTeX.

Thanks to Zarko I was able to get a working solution:

\documentclass[tikz,border=10pt]{standalone}
\usetikzlibrary{graphdrawing}
\usetikzlibrary{graphs}
\usegdlibrary{trees}
\begin{document}
\begin{tikzpicture}[>=stealth,every node/.style={anchor=west}]
\graph [tree layout, grow'=right, fresh nodes, level distance=3cm,
sibling distance=2ex, head anchor=west]
    {
        4 -> { 
          3 -> { 1 -> { 5, " " }, 2,2 },
          3 -> { 1, 2, 2 },
          3 -> { 1, 2, 2222 }
        } 
    };
\end{tikzpicture}
\end{document}

gives