Rather rough English translation, kayle is humming, ahri is asking soraka and zyra to find something, lux is jealous, shyvanna says something about jarven, cassie is giving Elise a heads up about whatever shyv is saying, oriana is worried about the water and morgana says something about a heart dying to oriana, I would like a more exact translation, but can't do it myself.

Kayle is humming, Ahri comments that it's her first time swimming here, Soraka and Zyra says it's their first time too, Lux seems to be jealous, Shyvana is self-commenting to be faster as Jarvan is waiting, Elise apparently bumped into Cassandra, which prompts her to tell Elise to be more careful and Elise saying sorry, Orianna worries whether it is OK to go into the water in her current body, and Morgana is assuring her that there's no problem with that.

At least that's what I think they are largely talking about.

jinx would disagree with that.