On Tuesday,  7 May 2019 at 13:22, Matt Price wrote:
> I thought that a latex src block with :exports results would work, but
> rather than a rendered graph I end up with a .png of the latex
> instructions themselves. Here's what I am trying:

It should work.  Try with the following header settings:

#+header: :exports results
#+header: :results file raw
#+header: :file image.png
#+header: :fit yes
#+begin_src latex
  \begin{tikzpicture}[node distance=4cm,minimum size=2cm]
    \node[draw,fill=blue!20!white] (humanities) {Humanities};
    \node[draw,fill=blue!20!white] (tools) [right of=humanities] {\parbox{3cm}{Computing \\ Tools and \\ Methodologies}};
    \draw[very thick,red] (tools) edge [out=270,in=270,->] (humanities);
  \end{tikzpicture}
#+end_src

--
Eric S Fraga via Emacs 27.0.50, Org release_9.2.3-327-g3375f0