Grayson said: "A moment of brilliance from Max won the game for us. He has certainly made an impact while on loan to us. We have already extended his loan until January, though Leicester can recall him at any time.
"We haven't discussed turning the loan deal into a permanent transfer as yet. It will be up to ourselves and Leicester to sort out whether that happens."
Leeds made it 20 home league games without defeat, but Grayson confessed: "Orient passed the ball around better than us.
"Some of the best passers and most intelligent players in our team had an off-night, which can happen during the course of a season. The tempo wasn't as high as usual, but give credit to Orient for playing so well against us with their 4-5-1 formation."