A group $G$ that can't be isomorphic to Aut($\mathcal D$) is
the direct sum of $\mathbb Z/p_i\mathbb Z$ over all $i\in B\oplus\overline B$, where $p_i$ denotes the $i$th prime number, and where $B$ has Turing degree not below a given presentation of Aut($\mathcal D$). For Richter, in her famous paper 

><cite authors="Richter, Linda Jean">_Richter, Linda Jean_, [**Degrees of structures**](http://dx.doi.org/10.2307/2273222), J. Symb. Log. 46, 723-731 (1981). [ZBL0512.03024](https://zbmath.org/?q=an:0512.03024).</cite>

showed this $G=G_B$ has isomorphism type of degree $[B]_T$, i.e., all presentations of $G_B$ have degree $\ge_T B$.

So to answer your question it remains to find a $B$ such that Aut($\mathcal D$) has a presentation that's $\not\ge_T B$.

Note that if Aut($\mathcal D$) is finite then it is not isomorphic to $G_B$ for any $B$, since the latter is countably infinite. So assume Aut($\mathcal D$) is infinite.

[Slaman and Woodin][1] showed that each automorphism $\pi$ of $\mathcal D$ is represented by an arithmetic function in the sense that there is an $n_0$ such that for all $\pi$ and all $X$, $\pi([X]_T)= [P(X)]_T$ where $P(X)=\{e\}({X^{(n_0)}})$.

Now we consider the necessary questions about numbers $e$ in order to present Aut($\mathcal D$).
We let $E=\{e_0<e_1<e_2<\dots\}$ be the set of those $e$ for which $P_e$ given by $X\mapsto \{e\}^{X^{(n_0)}}$ is an arithmetic representation of some automorphism.

The set $E$ is $\Pi^1_2$:
\begin{equation}
	\forall A(P_e(A)\text{ is total})
\end{equation}
\begin{equation}
	\forall A\forall B(A\le _T B\to P_e(A)\le_T P_e(B)),
\end{equation}
\begin{equation}
	\forall A\forall B(P(A)\equiv_T P(B)\to A\equiv_T B).
\end{equation}
\begin{equation}
	\forall A\exists B(P(B)\equiv_T A),
\end{equation}
(Actually, I think this can be reduced to $\Pi^1_1$ or a couple of jumps thereof: we can check whether there is another injective $e_j$ such that both compositions $e_i*e_j$, $e_j*e_i$ are the identity.)

The multiplication is given by defining $*$ by
$$
	P_{e_1* e_2} = P_{e_1}\circ P_{e_2}.
$$
We also have to mod out by equality, which we check by:
$$
e_1 \sim e_2 \iff \forall A (P_{e_1}(A)\equiv_T P_{e_2}(A))$$
Overall, taking $B$ to be $C^{(\omega)}$ where $C$ is a $\Pi^1_2$-complete set suffices.

  [1]: https://math.berkeley.edu/~slaman/talks/sw.pdf