Create similarity matrix

Question

I have a training set and a testing set of vectors. All the vectors are labeled.

For each labeled vector in the testing set, there are 3 vectors in the training set with the same label.

I'm using the cosine distance in order to calculate the similarity between the elements in the vectors. In the picture, we can see the results of applying the cosine distance similarity in a subset of 6 vectors from the testing set and 18 from the training set.

Now, I would like to create a similarity matrix of the labels. So, in this case, I'd need a matrix of 6x6 dimension, but I am not sure how to transform this matrix of scores to a similarity matrix.