Use the PSOUT command and write your drawing to an .EPS format file (encapsulated postscript).
Using Tools/Options (top right) in the EPS file dialog you can set scale, preview type and other parameters of the exported vector file.
Alternatively, you can define a PostScript plotter and PLOT to this device (.EPS), or use the PDF output from AutoCAD.
To control lineweights and colors in the PSOUT command (object-assigned lineweights are ignored), you can use the PSPROLOG variable. Set it e.g. to "*PSLWRGB" to search for a PSLWRGB.ps file in AutoCAD support path and load this postscript control file to change the default line weights and colors in the PSOUT output. See sample .PS files in the pslwgs.zip ZIP archive.