Edit in JSFiddle

<div class="cube spin">
  <figure class="side top">1</figure>
  <figure class="side left">2</figure>
  <figure class="side right">3</figure>
</div>

body {
  color: #fff;
  font: 600 24px/24px "Open Sans", "HelveticaNeue-Light", "Helvetica Neue Light", "Helvetica Neue", Helvetica, Arial, "Lucida Grande", Sans-Serif;
  margin: 12px 45px;
}
.spin {
  cursor: pointer;
  transform-style: preserve-3d;
}
.spin:hover {
    animation: spin 5s linear infinite;
}
@keyframes spin {
  0% {
    transform: rotateY(0deg);
  }
  100% {
    transform: rotateY(360deg);
  }
}
.cube {
  position: relative;
  width: 95px;
}
.side {
  height: 95px;
  line-height: 95px;
  position: absolute;
  text-align: center;
  width: 95px;
}
.top {
  background: #33cc54;
  transform: rotate(-45deg) skew(15deg, 15deg);
}
.left {
  background: #2db34a;
  transform: rotate(15deg) skew(15deg, 15deg) translate(-50%, 100%);
}
.right {
  background: #26973e;
  transform: rotate(-15deg) skew(-15deg, -15deg) translate(50%, 100%);
}