。
She hated the sight of that despicable man.
Literal
She [topic-は] that despicable man [object-を] see [nominalizer-の] [subject-が] was-disliked.
卑劣 ('despicable, cowardly, low') is a na-adjective for the morally contemptible, often paired with 行為 ('act') or 手段 ('method'). Stronger than just 嫌な ('unpleasant') — it implies real moral judgment. The structure 見るのが嫌だ uses の to nominalize 見る ('see'), then が to mark this nominalized action as the subject of the dislike-state 嫌だ — the same が-marking that goes with 嫌い, 好き, 怖い and other emotion predicates. Together: 'the seeing-of-him was hateful (to her).'