Option 1: search ebay (or a similar retailer) for "IP65 transparent" to find box-shaped waterproof enclosures with clear lids. Arrange electronics to your satisfaction, with the camera looking through the lid. Many sizes, but looks nothing like a normal CCTV camera.

Option 2: Search for "CCTV housing" to find boxes that look like old-fashioned outdoor CCTV cameras. Fewer size choices, but less weird-looking.