Cocircular Voronoi

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

.voronoi {
  fill-opacity: .5;
}

.delaunay {
  stroke: #000;
  fill-opacity: .5;
}

.links {
  stroke-width: 2.5px;
  stroke-dasharray: 5,5;
}

circle {
  fill: #000;
}

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

var width = 960,
    height = 500;

var vertices = d3.range(0, 2 * Math.PI + 1e-6, 2 * Math.PI / 5).map(function(d) {
  return [width / 2 + Math.cos(d) * 100, height / 2 + Math.sin(d) * 100];
});

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

var fill = d3.scale.category20c();

svg.selectAll(".voronoi")
    .data(d3.geom.voronoi(vertices))
  .enter().append("path")
    .attr("class", "voronoi")
    .style("fill", function(_, i) { return fill(i); })
    .attr("d", polygon);

svg.selectAll(".delaunay")
    .data(d3.geom.delaunay(vertices))
  .enter().append("path")
    .attr("class", "delaunay")
    .style("fill", function(_, i) { return fill(i); })
    .attr("d", polygon);

svg.selectAll("circle")
    .data(vertices)
  .enter().append("circle")
    .attr("transform", function(d) { return "translate(" + d + ")"; })
    .attr("r", 3.5);

svg.append("path")
    .attr("class", "links")
    .style("stroke", "blue")
    .attr("d", d3.geom.voronoi().links(vertices).map(line).join(""));

function line(d) {
  return "M" + d.source + "L" + d.target;
}

function polygon(d) {
  return d ? "M" + d.join("L") + "Z" : "";
}

</script>

Modified http://d3js.org/d3.v3.min.js to a secure url

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