PCA works by projecting a higher dimensional data to a lower dimension so it is not possible to reconstruct the exact original data from the lower dimensional representation.
None the less, you can get the approximate data back using the following equation.
Approx. Data = Projected Data x Coefficients’ + Mean
Refer to the following MATLAB code for an example
ingredients_hat = score * coeff' + mu;
You can refer to the documentation page for help with pca function.
Hope this helps.