。
The voices of playing children came drifting on the wind.
Literal
Playing-[ongoing-ている] children-of voices [subject-が] wind [on-に乗って] hear-[come-toward-てきた].
A lovely sensory sentence. 風に乗って ('riding on the wind, carried by the wind') is a poetic collocation — literally 'mounting the wind.' 聞こえてくる stacks the spontaneous 聞こえる ('be audible') with ~てくる ('toward the speaker') — 'came to be audible, drifted into hearing.' Every piece contributes to the evocative sensory imagery.