One needs to prove: if $K,L\subset G$ are compact subsets, there exist $x\in G$ such that $K\cap xL=\emptyset$. Consider the map $f:K\times L\to G$, $f(a,b)=ab^{-1}$. It can't be surjective ($K\times L$ is compact, hence the image of $f$ is compact). If $x\in G$ is not in the image of $f$ then $K\cap xL=\emptyset$.