All three options are grammatically correct, but the choice depends on the intended meaning.
"Humans" refers to the entire human species as a whole, and can be used in a more scientific or objective context.
"Human beings" is a more inclusive term that recognizes the individuality and diversity of people, and is often used in a more philosophical or humanistic context.
"A/the man" refers to a singular individual, and is more specific than the other two options. This would be appropriate if you are referring to a particular man or a specific type of man.
So, depending on the intended meaning, you could choose one of the following:
"His creative attention revolves around humans." (referring to the human species as a whole)
"His creative attention revolves around human beings." (referring to the diversity and individuality of people)
"His creative attention revolves around a/the man." (referring to a singular individual or a specific type of man)