Force Layout from Adjacency List

<!DOCTYPE html>
<meta charset="utf-8">
<style>

line {
  stroke: #ccc;
  stroke-width: 1.5px;
}

</style>
<body>
<script src="//d3js.org/d3.v3.min.js"></script>
<script>

var width = 960,
    height = 500;

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);

var force = d3.layout.force()
    .size([width, height]);

d3.json("graph.json", function(error, graph) {
  if (error) throw error;

force
      .nodes(nodes)
      .links(links)
      .start();

var link = svg.selectAll(".link")
      .data(links)
    .enter().append("line");

var node = svg.selectAll(".node")
      .data(nodes)
    .enter().append("circle")
      .attr("r", 5)
      .call(force.drag);

force.on("tick", function() {
    link.attr("x1", function(d) { return d.source.x; })
        .attr("y1", function(d) { return d.source.y; })
        .attr("x2", function(d) { return d.target.x; })
        .attr("y2", function(d) { return d.target.y; });

node.attr("cx", function(d) { return d.x; })
        .attr("cy", function(d) { return d.y; });
  });
});

</script>

https://d3js.org/d3.v3.min.js