Stardraw does not save as Viso format, but Visio is advertised as supporting certain common file formats, e.g. DWG & DXF, that Stardraw does Save As.  Select File | Save As, and choose the appropriate format from the Files of Type dropdown, then just open it in Visio - again, choose the format in the File of Type dropdown.

You can also just copy from Stardraw and Paste into Visio.  The appropriate technique really depends on what you want to do with the drawing in Visio.

I hope this is helpful

Kind regards,
Rob Robinson
Stardraw.com

John H