wow, this brings back the memories when I did P&G projects. I had to do so called "English Logic" diagrams. I did this one project where every PLC programmer quit and got stuck doing 10 unit operations and conveyor in a paper towel factory room. It was just two lines of towels. I think I had like 10 cad operators behind me doing cad. This was like the 1996-8 time frame. After that mind numbing experience I swore off doing that stuff ever again.
I remember some of the other companies I worked for had some sharp cad operators that had semi automatic tools or Lisp routines that generated a lot of the work. Like drawing the different symbols, and or, xor gates. The gate would represent either contacts in series or in parallel Maybe look at cad forums and ask around.
I remember Taylor software had a program that generated these type of diagrams but that was like 30 years ago. I bet they are out of business, it was a company out of Canada.
I would put an adder in your quote to provide these diagrams. Get a 3rd party cad house to quote this for you based on the specs that the end user would give you. Once they see the price they would back off asking for them.