\documentclass[border=2pt]{standalone}
% Drawing
\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\usetikzlibrary{calc}
% Notation
\usepackage{physics}
% Styles
\tikzset{mass/.style={inner sep = 2pt}}
\begin{document}
\begin{tikzpicture}
% %Grid
% \draw[thin, dotted] (0,0) grid (8,8);
% \foreach \i in {1,...,8}
% {
% \node at (\i,-2ex) {\i};
% }
% \foreach \i in {1,...,8}
% {
% \node at (-2ex,\i) {\i};
% }
% \node at (-2ex,-2ex) {0};
% Coordinates
\node[mass] (O) at (0,0) {};
\coordinate (A) at (3.5,3);
\coordinate (B) at (5.5,2.5);
\coordinate (C) at (7.3,4);
\coordinate (D) at (6.5,5.5);
\coordinate (E) at (4,6);
\coordinate (F) at (2.5,4);
\node[mass] (G) at (3,3.7) {};
\node[mass] (H) at (6,3) {};
%% Nodes