No pictures but it's easy to figure position. They have to be where the bolts will go through the decking into the open cockpit area and be inline front to back with the rachet block. Which is also mounted through the front cockpit lip on the center line.
I would recommend when you purchase the cam cleats to buy angled block risers as well.
The cam cleats mounted directly to the deck form an angle with the mainsheet that keeps it from holding very well as the mainsheet's angle tends to pull it from the cleat. The angled riser bock do two things #1 match the angel of the cleat to the angle of the main sheet and #2 raise the mainsheet coming out of the cleat so you can hold it over the deck area without also putting upward pressure on the mainsheet and tending to pull it up out of the cleat.
When you hold the mainsheet from the block to the edge of the deck the angle blocks need to follow that angle. Tilting the block into the same plane as the mainsheet.
Don't worry if you get them backwards you'll know it the first time you try to cleat the mainsheet. They reverse easily. I know from experience.