bgraf,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
.act { background-color: #FF1493; margin: 8px; }
</style>
<script>
window.addEventListener('DOMContentLoaded', function() {
var menuServicesCategory = document.querySelectorAll(".menu_servicesCategory li a");
[].forEach.call(menuServicesCategory, function(item) {
item.addEventListener('click', function(event) {
event.preventDefault();
[].forEach.call( menuServicesCategory, function(el) {
el == item ? el.classList.add('act'): el.classList.remove('act');
});
});
});
});
</script>
</head>
<body>
<ul class="menu_servicesCategory">
<li><a href="">1</a></li>
<li><a href="">2</a></li>
<li><a href="">3</a></li>
<li><a href="">4</a></li>
<li><a href="">5</a></li>
<li><a href="">6</a></li>
<li><a href="">7</a></li>
<li><a href="">8</a></li>
</ul>
</body>
</html>