\begin{tikzpicture}
    \node[color=red] (min) at (0,-1.5) {$\varnothing$};
    
    
    \node[color=red] (p0) at (-3,0) {$(0,+)$};
    \node[color=red] (pp) at (-1,0) {$(+,+)$};
    \node[color=darkgray] (pn) at (1,0) {$(+,-)$};
    \node[color=blue] (0p) at (3,0) {$(+,0)$};
    
    \node[color=red] (p0-pp) at (-4,2) {$\overset{12}{(0,+)<(+,+)}$};
    \node[color=darkgray] (p0-pn) at (-1,2) {$\overset{\bar{2}\bar{1}}{(0,+)<(+,-)}$};
    \node[color=blue] (0p-pp) at (2,2) {$\overset{21}{(+,0)<(+,+)}$};
    \node[color=purple] (0p-pn) at (5,2) {$\overset{\bar{1}\bar{2}}{(+,0)<(+,-)}$};
    
    \draw[color=red, ultra thick] (min.north) -- (p0.south);
    \draw[color=red, ultra thick] (min.north) -- (pp.south);
    \draw[dashed] (min.north) -- (0p.south);
    \draw[dashed] (min.north) -- (pn.south);
    \draw[color=red, thick] (p0.north) -- (p0-pp.south);
    \draw[dashed] (p0.north) -- (p0-pn.south);
    \draw[color=blue, ultra thick] (0p.north) -- (0p-pp.south);
    \draw[color=red, ultra thick] (pp.north) -- (p0-pp.south);
    \draw[dashed] (pp.north) -- (0p-pp.south);
    \draw[dashed] (pn.north) -- (0p-pn.south);
    \draw[dashed] (0p.north) -- (0p-pn.south);
    
    
    \draw[color=darkgray, ultra thick] (pn.north) -- (p0-pn.south);
\end{tikzpicture}
