。。
You'd better stay quiet. There's no point talking to him.
Literal
Be-silent-was [way-方] [subject-が] good. Him [to-に] talk-[even-ても] useless is.
Two-clause structure: a recommendation followed by its justification. The first clause is the standard ~た方がいい ('better to X'). The second uses ~ても無駄 ('even if you X, it's useless') — a fixed frame for 'no point in X-ing.' 無駄 ('waste') as a na-adjective predicate fits naturally after the concessive ~ても.