Let's first consider the case of $\mathbb{F}_3(C_3)$. This is isomorphic to $\mathbb{F}_3[x]/(x^3)$, the isomorphism is given by sending $g\mapsto 1+x$, where $g$ is a chosen generator of the cyclic group $C_3$. (compare the answer to this question. This algebra is obviously given by a quiver with relations, namely the 1-loop quiver with relation $x^3=0$.
For $C_3\times C_3$ either one uses the same method or one notes that $\mathbb{F}_3(C_3\times C_3)=\mathbb{F}_3(C_3)\otimes_{\mathbb{F}_3} \mathbb{F}_3(C_3)$ which is therefore isomorphic to $\mathbb{F}_3[x]/(x^3)\otimes_{\mathbb{F}_3} \mathbb{F}_3[y]/(y^3)\cong \mathbb{F}_3[x,y]/(x^3,y^3)$. This is already a quiver with relations, namely the 2-loop quiver (as Aaron suggested) with relations $x^3=0$, $y^3=0$, and $xy=yx$.