How to cluster handwritten digits using k-means with K=10 ?

I have to implement K-means algorithm for K=10 on handwritten digits data. The data matrix is 2500 X 784,i.e there are 2500 data points each with dimensions 784 .After clustering,I have to label each cluster with the digit that occurs most frequently in it and then find the classification accuracy with this unsupervised method.

Dimensions are not to be reduced with PCA or any other dimensionality reduction technique.

But I am not sure how to show the plot having different clusters with their labels (as each data has 784 dimensions) and how to determine which point in the cluster corresponds to which digit. Please help me with this.I am new to Matlab !!!