Sketch again (6)
'sketch again' is the definition.
(to sketch or draw again)
This is all the clue.
(Other definitions for redraw that I've seen before include "Adjust" , "plan afresh" , "Design again" , "Sketch again" , "Pick over" .)
(Other definitions for redraft that I've seen before include "Make a copy" , "Change outline" , "second edition" , "Corrected version" , "Write (document) differently" .)