Confusing title I know but I think it describes this process correctly. Okay here goes:
In ArcCatalog, open the ArcToolBox.
Now double-click on the “Set Cad Alias” tool under Conversion Tools –> To CAD
Now in the input table select the data layer (input feature) you want to convert to AutoCAD.
The Field Info box should now be populated with field names.
Select the field that you want to use as the layer names for your AutoCAD file.
Now under the Alias Name select the field type you want (in this case Layer)
Now Click OK, making sure you’vc not got this file opened in a ArcMap document.
Next double-click on the “Export to CAD” tool under Conversion Tools –> To CAD in the ArcToolbox
Select you data layer(s) (input feature).
Make sure you’ve select the correct Output Type (I tend to use DWG_R2000)
And make sure you’ve chosen a suitable Output file name and location.
Now Click OK
Open it up in AutoCAD to make sure its worked.