Kayle is at her weakest in the early game. Try to abuse her weakness by playing aggressive and getting kills. Putting her behind in the early game will reduce her ability to carry later on in the game.
Keeping the minion wave closer to your side of the map will force Kayle to overextend for farm. Once she walks up and tries to last hit, you could play aggressive and try to all-in her.
Once Kayle hits level 6 and unlocks her Ultimate R, she will also become ranged and she’ll find it easier to last hit. She will be able to also poke you down and trade more effectively. You’ll need to be more strategic when trying to fight her from now on.
Try to end the game as quickly as you can as the longer the game goes, the stronger Kayle becomes.
Kayle will tend to be split pushing during the mid-game. You can use this time to force a team fight with the numbers advantage while she is pushing in a side lane.
Kayle is rather vulnerable when her Ultimate R is on cooldown. Try to force fights and kill her while her Ultimate R is down.
Kayle is really weak in the early game. Try to abuse her as much as possible so she is forced to back early and delay her first major power spike.
Once Kayle hits level 6, she will become ranged and get a lot of added protection thanks to her Ultimate R. You need to always consider her Ultimate R when trying to fight her post level 6.
As Kayle becomes stronger as the game goes along, you really need to end the game as quickly as possible. If you cannot end the game and it gets to late game, you are gonna find it difficult to win.