In the suttas, what is mentioned in most cases is that “a certain Deva came to see the Buddha, and the light of that Deva lighted up the vicinity of Jetavanaramaya.”
- See, for example, “Oghataraṇa Sutta (SN 1.1)“: “Then, late at night, a glorious deity, lighting up the entire Jeta’s Grove, went up to the Buddha, bowed, stood to one side, and said to him,…”
I have not seen a sutta specifically state that people saw a Deva‘s body.
- However, if they want to, they can “make up a dense body for the humans to see them.”
- There is a sutta that says the following. Once, a Deva came to see the Buddha and “could not balance his subtle, almost weightless body and was having a hard time standing up.” So, the Buddha asked the Deva to “make up a dense body so that he could stand firm.” I don’t recall the name of the sutta.
By the way, there are many suttas, roughly from SN 1.1 (above sutta) to SN 6.10, that describe the visits of various Devas and Brahmas to see and discuss dhamma concepts with the Buddha.
