Put the whole pot into a pan of water for 15 minutes to make sure the core of the media immediately underneath the trunk has been wet-out. Increase the amount of sunlight getting to the whole tree by cutting off all the leaves at the base of the leaf, leaving the petiole in place. The petiole guards the new buds in the axils and will be kicked off as the bud expands. Then place it in half-day (eastern is best) sun. A tree without leaves can't get too much sun unless it is allowed to dry out. Water it when it needs it. Do not keep it sodden, but don't let it dry out either. This is a bad time of the year to have this happen because if it leafs out it will be using next spring's buds and will have less than the normal amount of time to replace those buds this year for next spring. So, it may come back to limited life only to go to sleep and have a silent spring. Unfortunately, your only option is to resuscitate now and keep your fingers crossed.
In the future, you can put single trees under a downspout with a screen or other deflector on the media surface so a heavy downpour doesn't wash the soil out, but you will get some drippings off the roof every dew-point, usually daily. And have your timer on, too. Too wet for one week is tolerable, especially as opposed to what you have now.