The above confusion matrix chart can only be obtained using the function plotconfusion(targets,outputs) which requires true labels targets and predicted labels outputs, specified as categorical vectors, or in one-of-N (one-hot) form.
Since you have confusion matrix already, you cannot use the above function and can only use confusionchart function.
If you are looking only for the percentages to have in the chart then you can use the Normalization Name-Value Pair argument and set it to 'total-normalized' or 'row-normalized' or 'column-normalized'.
A=[6 1 0 0 ;0 6 0 1; 0 0 7 1;1 0 0 5];
M = confusionchart(A,{' A',' B',' C','D'},'Normalization','total-normalized')
