In order to get to Xerokampos from Heraklion the soonest way is to go through Ierapetra.
After Agios Nikolaos and Pahia Ammos you turn right towards Ierapetra. Before entering Ierapetra you have to turn left towards Sitia.
You will pass through Makrygialos and you will continue straight ahead.
After Lithines village and just before you enter Papagianades village you have to turn right towards the villages Armenoi, Chandras, Ziros.
After passing through Ziros village you will have to turn right towards Xerokampos. You will follow for about 15Km a snaky road with great view to the Livean Sea and you will get to Xerokampos.
In order to get to Xerokampos from Sitia the soonest way is to go through Palaikastro and Zakros.
You will pass through Palaikastro and you will continue towards Zakros.
As soon as you pass through Zakros turn right towards Xerokampos and follow the asphalt road. After 9km you will be in Xerokampos.
Alternatively from Sitia if you wish so you can drive towards the plateaus with the windmills (25km of asphalt road) and the villages Armenoi, Chandras, Ziros and from there to continue towards Xerokampos.