Searching for style in an dirty outdoor job

I work in the utilities industry, and I work a lot. 60 hour weeks are common, and I feel like the slim bit of personal time I get are spent being too tired to really pay attention to what I'm wearing. In my quest to "dress confidently" I have failed to come up with any ideas for my job. To be specific, I occasionally have to get in communication manholes (not sewers, but dirty enough to pass for them sometimes) and I do quite a bit of kneeling/crouching including on dirty/muddy/wet surfaces.

How can I blend my career with my desire to dress better? This isn't a typical "style guide" request so I wasn't able to find anything in the sidebar. I am about 6' with an average build. I want to convey a clean and mature look without wearing the same boring jeans/carrhart combo. Most of my peers shop at Walmart/Target exclusively and I am tired of looking like a bum. Any ideas?

EDIT: I want to stress that I don't want to look unusually well dressed for the industry. I do engage the public a bit, but also work with contractors and utility representatives, so I don't want to look like I'm trying too hard if that makes sense.