DiagrammeR neato org chart (howto add labels to grViz?)

How do I add names (or labels) to a DiagrammeR GraphViz layout? I'd like to add names to each dot below, and I'd like them to be in an organized fashion, not overlapping anything else, a la ggrepel style. You can use any names you wish for the following example. This is going to basically be an org chart. Thank you.

library(DiagrammeR)
grViz("
digraph neato {

graph [layout = neato]

node [shape = circle,
      style = filled,
      color = grey,
      label = '']

node [fillcolor = red]
a

node [fillcolor = green]
b c d

node [fillcolor = orange]

edge [color = grey]
a -> {b c d}
b -> {e f g h i j}
c -> {k l m n o p}
d -> {q r s t u v}
}")

after the node, add [label = 'your label']. You can declare a node's label separately or inline.

grViz("
digraph neato {

graph [layout = neato]

node [shape = circle,
      style = filled,
      color = grey,
      label = '']

node [fillcolor = red]
a [label='a']

node [fillcolor = green]
b c d

node [fillcolor = orange]

l [label = 'llllllllllllll', fixedsize = true, width = 0.5]

edge [color = grey]
a -> {b c d}
b -> {e f g h i j}
c -> {k l m n o [label = 'o'] p [label = 'p']}
d -> {q r s t u v}
}")