This one took a loooong time to tune up. The code is quite simple though:

canvasWidth = 600;
canvasHeight = 400;

path = canvasWidth/14;
n=30
c =0;
size = 8;


function setup() {
  createCanvas(canvasWidth, canvasHeight);
}

function draw() {
  background(0)
  c+=0.05;
  
  cosOffset = sin(c/300) * 5;  
  
  for(let i = n; i>=0; i--){
    fill(255-i*255/n);
    circle(canvasWidth/2 + cos(c+i*cosOffset)*path, canvasHeight/2, size + i*size);
  }
}