Electronic Design Software for Large Electronics
As AngryEE mentioned, you want to draw wiring diagrams rather than schematics.  These are designed to be constructed by hand, rather than by a PCB design shop, and they have very different regulations than PCBs.
One thing that you'll quickly discover is that you must label all your wires.  According to NFPA 79, the Electrical Standard for Industrial Machinery, you must use the following voltage-based scheme for your electrical wiring:


Black: AC hot
Red: Switched AC hot
Yellow: AC hot from a another source
White: Neutral
Red with White tracer: switched neutral
Green or Green with tracer:  ground/earth ground
Blue: DC voltage like the output of your power supply
White w/Blue tracer: DC common


The result is that I'm likely to have hundreds of blue wires snaking their way through Panduit to various terminal blocks, IO controllers, and other peripherals on DIN rails in even a small 20&quot; panel.  This means that you must have an intelligent way to name, label, and locate wires when you do updates or rework.
The usual method is to use a ladder diagram or ladder schematic (note that these are distinct from the 'ladder logic' used for programming PLCs, which often occur in the same areas...).  I've got a modicum of experience with this (as an intern at a company with probably 600 electrical panels on our production floor).  People wiser than I have decided that we'll use AutoCAD Electrical; (note that this is not an endorsement, I find the program to be a royal pain to use) but there are probably other programs for the purpose.  It comes with symbols for devices from many of the most popular manufacturers, though I don't know that the above supply will be in it.  Here's my addition of a Phoenix supply to a circuit I'm working on:

with some distribution and fusing here:

Those images (along with another couple hundred rungs) form the wiring diagram.  This all goes into the panel diagram, which is the wiring equivalent of a PCB layout:

Each of these terminals is listed on the wiring diagram, so wiring the panel is simply a matter of laying out the components as shown in the panel diagram, then opening the wiring diagram and working down the rungs of the ladder, printing labels and connecting wires to the indicated terminal.
This is the best way to deal with large boxes of electronics.  It may be unfamiliar to you, but it's a different task than designing a PCB.