PSD for block codes

Hi Matlab experts,

Can somone please assist with a matlab code that can draw the PSD of a non-binary codebook? An example codebook is as given below.

C=[0 1 2 5 4 3; 0 1 3 5 4 2; 0 4 2 5 1 3; 0 4 3 5 1 2;
5 1 2 0 4 3; 5 1 3 0 4 2; 5 4 2 0 1 3; 5 4 3 0 1 2;
1 0 2 4 5 3; 1 0 3 4 5 2; 4 0 2 1 5 3; 4 0 3 1 5 2;
1 5 2 4 0 3; 1 5 3 4 0 2; 4 5 2 1 0 3; 4 5 3 1 0 2;
2 1 0 3 4 5; 3 1 0 2 4 5; 2 4 0 3 1 5; 3 4 0 2 1 5;
2 1 5 3 4 0; 3 1 5 2 4 0; 2 4 5 3 1 0; 3 4 5 2 1 0;
2 0 1 3 5 4; 3 0 1 2 5 4; 2 0 4 3 5 1; 3 0 4 2 5 1;
2 5 1 3 0 4; 3 5 1 2 0 4; 2 5 4 3 0 1; 3 5 4 2 0 1] 

Attached is the expected PSD graph of this codebook. I have a number of non-binary codebooks which I want to compare their PSDs using this method.