Having worked for 3 years looking to secure a graduate job of my choice, I have concluded that getting a graduate job if you are a foreign student is in one word, impossible. I do not know why, could be the difference in working culture, or the companies expect a certain kind of communication style, but it is impossible to get into a graduate scheme. The only companies that truly recruit foreign grads are the big 4, which due to this economy have stopped hiring. But for anyone wanting to try different avenues, it is better to stop dreaming and head back or settle for a smaller job in UK, which can be excruciatingly difficult.
But anyone who still wants to try, good luck but keep your expectations as low as possible