There is no way to view or edit post drafts using Facebook on a phone or tablet.
To create a new draft, click +Create at the top-right corner.
If you want to post without editing the draft, click the down-arrow next to “Edit” and select Publish to publish now, or Schedule to choose an automatic posting date.
Click the button under “News Feed” and select Share Now. Click “Save. " This changes the “Share Now” button at the bottom to a “Save as Draft” button instead. Click the Save as Draft button to save your progress.
If you want to share the post right now, make sure Share Now is selected in the menu below “News Feed. " If you see something else there, click the button and select Now from the list. Then, click Share Now at the bottom to share your post. If you want to schedule the post for a later date (or backdate it to a previous date), select Schedule or Backdate, select a date, and then click Schedule or Backdate to confirm.