Pictures you can find all over the internet.
duck.com or yandex.com and press on the word/button “images” and before you search on the exact product name of you 1009 like: CCR1009-7G-1C-1S+PC
The SFP cages have holes in the top that let hot air out and you should not cover all with heatsinks. Also a heatsink need that the SFP is in contact with the cage. There is a little air-gap between the SFP module and the cage so that is not as effective. You are then only cooling the cage. The cage is heated by the heat radiating from the module and heat transferred back through the PCB.
The best cooling is moving cool air over the components getting hot. If you have a fan-less one then you could think of attaching a fan to the outside drawing air out through the air vents. Example see my active cooling the huge passive plate covering the RB4011 and the link is in my signature.