您只需要添加 TikZ 库babel
:
\documentclass[tikz,
border=3mm]{standalone}% solution work at any documentclass
\usepackage[slovak]{babel}
\usepackage{tikz}
\usetikzlibrary{graphs,babel} % <-- added library "babel"
\begin{document}
\tikz \graph { a -> {b, c} -> d };
\end{document}