There are a handful of deities who are portrayed as eternally young, and a sprinkling more who are given prominent portrayals as youths while often maintaining older appearances, as well.
In the former category, we have Eros, Apollon, Adonis, Ganymedes, Hyakinthos/Hymenaois, Hebe, Artemis, Iris, Persephone, the Moisai, the Khairetes, and by ancient potrayals, Hekate —just off the top of my head. In the latter category, we have Dionysos, Hermes, Aphrodite (more-or-less), and Hestia (again, off the top of my head).
The youthful deity means something, even in the deity who is only sometimes young, or if the deity is worshipped by clearly aged people. Youth represents many things: Vitality, strength, beauty, innocence (but not with the Christianised perversion of the term’s various implications and nuance), freedom, passion, virility….
There is also a wisdom to youth, a wisdom that never stops seeking, for the young are naturally quite curious and can become quite passionate about the things they’ve learned. The old mistake this passion for a lack of wisdom, or even a lack of knowledge, but that sort of passion serves a wisdom that hasn’t yet learned to second guess itself, a wisdom that knows better than to sell out or cash in, and a wisdom that understands that there are more things important than what the neighbours think.
Furthermore, if I’ve learned anything from television about youth, it’s that the young and young at heart tend to be especially conscious of the fact that appearances matter, that when operating from the thin illusory veil of Free Will, the appearances we put forward can have a transformative effect on ourselves and those around us and, if anything, this can illustrate the true lack of Free Will that exists amongst mortals when something inanimate can have that much power, when a change of top from a Fred Perry styled short sleeve to a long-sleeved poet’s shirt (or vice-versa) can create a marked change in the way one is treated and the people it will attract and deflect.