It is very simple though a bit time consuming cleaning all the veggies.
1 Pound Vegtable Rotini (multi colored pasta)
1 or 2 large Green Peppers
1 large Yellow Pepper
1 large Red Pepper
1 large Orange Pepper
and any other colored peppers you may have or want.  I added Chocolate & Lavender Peppers as well this time and at the Nodrog Specialty as I had them in my garden.
2 or 3 Cucumbers
1 large sweet onion (I use Vadalia's when available, including this time.  I buy them before the season ends and store them in the fridge).
3 or 4 stalks of celery
2 or 3 large tomatoes
1 Can of black olives either large size or sliced.  If you buy the whole ones in the large size silce them into 3 or 4 slices each.
1 bottle of Wishbone Robusto Italian dressing
Cook pasta
cut peppers, celery, cucumbers & tomatoes into bite size or slightly smaller pieces.   I tend to leave the tomatoes in larger pieces and add more as we love tomatoes.  Cut onions into small pieces.  Add sliced olives and mix all together. 
Add most of the bottle of dressing 10 minutes or so before serving as it tends to soak it up and go slightly flat if left too long.  Stir in and stir up periodically.  Add more dressing as needed.
This makes a huge bowl so you can either add or cut back on the amount of veggies.  When camping at dog shows I have even used a large clean dishpan.  I added more to both the one at the hunt trial and the one at the specialty so there would be more to go around.  The amount of pasta always stays the same unless you really want to get carried away...........grin.