HoldForm @@ {Factor[x^105 - 1]} /. k_ x_^n_ :>
RuleCondition[With[{b = Style[Abs[k], Red]},
If[Internal`SyntacticNegativeQ[k], -1, 1] HoldForm[b x^n]], Abs[k] > 1]

Use Highlighted[Abs[k]] instead of Style[Abs[k], Red] to get

See also: Replacement inside held expression
Update: Displaying in TraditionalForm:
HoldForm @@ (TraditionalForm /@ {Factor[x^105 - 1]}) /. k_ x_^n_ :>
RuleCondition[With[{b = Style[Abs[k], 14, Red]},
If[Internal`SyntacticNegativeQ[k], -1, 1] HoldForm[b x^n]], Abs[k] > 1]

We can get Highlighted looks using
HoldForm @@ (TraditionalForm /@ {Factor[x^105 - 1]}) /. k_ x_^n_ :>
RuleCondition[With[{b = Framed[Style[Abs[k], 14], Background -> Yellow,
FrameStyle -> None]},
If[Internal`SyntacticNegativeQ[k], -1, 1] HoldForm[b x^n]], Abs[k] > 1]
