The drawing that you are showing is a basic interconnect drawing. It appears you are drawing the elevations of different equipment that you are interconnecting. There will be no drawing packages that have libraries of your particular interfaces. These elevation drawings can often be provided by the different manufacturers of the product, however, in many cases, you will have to draw the elevations yourself and add them to your library.
With that said, Autocad will do nicely for these drawings, as well as Dassault Systems (the people who make Solidworks) has a 2d package called DraftSight that is excellent. The other side of the coin is to use a 3d modeling program, such as SolidWorks, to model your different interfaces and then pull elevations from different sides as needed in 2d. However, in order to complete your interconnection diagram, you will need a 2d program to do so.
MS Visio can do this, but it is not as concise as Autocad or DraftSight. Visio will take in DXFs of the elevations, however, as well as Autocad and DraftSight.
If pricing is an issue, DraftSight is the less expensive of the 3 that I mentioned.
You mentioned schematics, and all of the above mentioned can do schematics, but for parts libraries, you would probably want DraftSight or Autocad. The libraries that come with packages is always lacking, however, you should be able to find suitable electrical/electronic symbols that are DXF or DWG type files all over the internet to add to your library.
Hope this helps...