"过分戏剧性地表达" can be translated into English as "overdramatize an expression" or "express something in an overly dramatic manner".
Both phrases convey the idea of presenting something with excessive theatricality or exaggeration. For example:
He tends to overdramatize his emotions. （他倾向于过分戏剧化地表达自己的情绪。）
She expressed her disappointment in an overly dramatic manner. （她以一种过分戏剧化的方式表达了她的失望。）