You can't use から in your sentence これは、私が毎日コーヒーを買う、きっさてんです(This is a cafe where I buy a coffee everyday).
If you want to use から, you need to change the structure of the sentence like 私は、この喫茶店から毎日コーヒーを買う(I buy a coffee everyday from this cafe). However this sentence is a bit unnatural and 喫茶店で is more natural. If you buy something from someone, から is used but で isn't used like 私は彼から本を買った(I bought a book from him).
That is to say, で買う means "buy at place", から買う means "buy from owner", so I feel 喫茶店から買う is a bit unnatural because 喫茶店 is a place.