yEd enables to make irregular hexagons only (https://www.edplace.com/userfiles/image/Hexagon1.png).
Would it be possible to add regular hexagons like this as shape nodes?
yEd supports importing your own symbols - please see How can I use my own node symbols in yEd? for details. Thus, if you do not like yEd's hexagon, just import a JPG, PNG, or SVG version of a hexagon you do like.