Chart.js 棒グラフのサンプル

<div style="width: 300px;">
  <canvas id="myChart"></canvas>
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.1/Chart.min.js"></script>

var ctx = document.getElementById('myChart');
var myChart = new Chart(ctx, {
  type: 'bar',
  data: {
    labels: ['赤党', '緑党', '青党'],
    datasets: [{
      label: '投票数',
      data: [10000, 5000, 7000],
      backgroundColor: [
        'rgba(255, 0, 0, 0.2)',
        'rgba(0, 255, 255, 0.2)',
        'rgba(0, 0, 255, 0.2)'
      ],
      borderColor: [
        'red',
        'green',
        'blue'
      ],
      borderWidth: 1
    }]
  },
  options: {
    scales: {
      yAxes: [{
        ticks: {
          beginAtZero: true,
          callback: function(val) {
            return val + '票';
          }
        }
      }]
    }
  }
});