Examine the language in the versus.
“Let”. First and foremost, “let” is a proclamation said to those of equal value of authority. If God was speaking to created beings, or “lesser gods”, or even just speaking to Himself in a Unitarian sense He would’ve said: “I will make…”
“Us and Our”. A purality, but used in a equal sense.
“Image and Likeness”. I believe St. Aquinas said it perfectly when writing the Contra Gentiles:
[14] This idea even seems to find support in the Book of Genesis (1:26), where, after the statement, “Let us make man to Our image and likeness,” it is added: “God formed man of the slime of the earth; and breathed into his face the breath of life.” From this text some wished to infer that the soul is of the very nature of God. For, since he who breathes into another’s face puts forth into the latter numerically the same thing that was in himself, holy Scripture itself would here seem to imply that God put into man something divine in order to give him life.
[15] But the likeness in question is no proof that man is a part of the divine substance, for man’s understanding suffers from many defects—which cannot be said of God’s. This likeness, then, is rather indicative of a certain imperfect image than of any consubstantiality. And, indeed, Scripture implies this in saying that man was made “to the image” of God. And thus the “breathing” of which Genesis speaks signifies the pouring forth of life from God into man according to a certain likeness, and not according to unity of substance. So, too, “the spirit of life” is said to have been “breathed into his face,” for, since the organs of several senses are located in this part of the body, life is more palpably manifested in the face. God, therefore, is said to have breathed the spirit into man’s face, because He gave man the spirit of life, but not by detaching it from His own substance. For he who literally breathes into the face of someone—and this bodily breathing is evidently the source of the Scriptural metaphor—blows air into his face, but does not infuse part of his substance into him.
Also in Genesis, another chapter has clues of the Trinity, I ask you to read chapter 18 and dissect every word.