أحسن الله إليكم If someone is talking to me during the jummah khutbah can I put my pointer finger on my lips gesturing to him to be quiet without saying any words?

Yes, gesturing is what is done which is the saying of the jumhoor, because what the hadith forbids is speaking, for the Prophet ﷺ said that if you say to your companion be quiet on Friday while the imam is delivering the khutbah, you have engaged in idle talk (agreed upon). Ibn Umar raḍiyallāhu ʿanhu was seen gesturing to a man during the khutbah, and Ibn Rajab raḥimahullāh reported that the scholars do not differ over the permissibility of gesturing.