Example using two separate CartoDB layers

<!DOCTYPE html>
<html>
  <head>
    <title>Two CartoDB layers with CartoDB.js</title>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
    <meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
    <link rel="shortcut icon" href="https://cartodb.com/assets/favicon.ico" />
    <style> html, body, #map { height:100%; padding:0; margin:0 } </style>
    <link rel="stylesheet" href="https://libs.cartocdn.com/cartodb.js/v3/themes/css/cartodb.css" />
  </head>
  <body>
    <div id="map"></div>
    
    
    <script src="https://libs.cartocdn.com/cartodb.js/v3/cartodb.js"></script>

// add a nice baselayer from Stamen 
        L.tileLayer('https://{s}.tile.stamen.com/toner/{z}/{x}/{y}.png', {
          attribution: 'Stamen'
        }).addTo(map);

cartodb.createLayer(map, {
          user_name: 'xavijam',
          type: 'cartodb',
          sublayers: [{
            sql: "SELECT * FROM cleaning_guys WHERE cartodb_id < 5",
            cartocss: '#cleaning_guys {marker-fill: blue;}',
            interactivity: 'cartodb_id'
          }]
        })
        .addTo(map)
        .on('done', function(lyr){
          setTimeout(function(){
            lyr.setCartoCSS('#cleaning_guys {marker-fill: yellow;}');
          },5000);
        })

cartodb.createLayer(map, {
          user_name: 'xavijam',
          type: 'cartodb',
          sublayers: [{
            sql: "SELECT * FROM cleaning_guys WHERE cartodb_id > 5",
            cartocss: '#cleaning_guys {marker-fill: red;}',
            interactivity: 'cartodb_id'
          }]
        }).addTo(map)
      }
 
      window.onload = main;
    </script>
  </body>
</html>

Modified http://libs.cartocdn.com/cartodb.js/v3/cartodb.js to a secure url

https://libs.cartocdn.com/cartodb.js/v3/cartodb.js