How to draw a graph with pgfplots in LaTeX

Question

What is the simplest way to draw graph like this in Latex?

I tried but I don't know how to write a code for that.

\documentclass{report}
\usepackage{tikz}

\begin{document}

\begin{tikzpicture}
\draw[help lines, color=gray!30, dashed] (-4.9,-4.9) grid (4.9,4.9);
\draw[->,ultra thick] (-8,0)--(8,0) node[right]{$x$};
\draw[->,ultra thick] (0,-8)--(0,8) node[above]{$y$};

  % First, define nodes
  \draw (0,0) node[circle, inner sep=2pt, fill=black, label={below:{$A(0,0)$}}] (A) {};  
  \draw (5,0) node[circle, inner sep=2pt, fill=black, label={below:{$B(5,0)$}}] (B) {};  
  \draw (2,2) node[circle, inner sep=2pt, fill=black, label={below:{$C(2,2)$}}] (C) {}; 
  \draw (1.5,-2) node[circle, inner sep=2pt, fill=black, label={below:{$D(1.5,-2)$}}] (D) {}; 

  % Draw curved path
  \draw[black]  (A) -- (B);
  \draw[black]  (A) -- (C);
  \draw[black]  (A) -- (D);
  \draw[black]  (C) -- (B);
  \draw[black]  (D) -- (B);
  \draw[red]  (A) .. controls +(-0.1,1.5) and +(0.5,2).. (C);
  \path[->] (A)  edge [bend left] node {aaaa} (C);

\end{tikzpicture}

\end{document}